Report on Ibu (Indonesia) — 29 March-4 April 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 March-4 April 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Ibu (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 29 March-4 April 2017. Smithsonian Institution and US Geological Survey.
1.488°N, 127.63°E; summit elev. 1325 m
All times are local (unless otherwise noted)
PVMBG reported that an eruption at Ibu at 0058 on 29 March generated an ash plume that rose to an altitude of 1.8 km (5,800 ft) a.s.l. and drifted N. Another event at 0757 on 3 April produced an ash plume that rose to an altitude of 1.7 km (5,500 ft) a.s.l. and drifted S. Seismicity on both days was characterized by events indicating explosions and avalanches.
Geologic Background. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, contained several small crater lakes through much of historical time. The outer crater, 1.2 km wide, is breached on the north side, creating a steep-walled valley. A large parasitic cone is located ENE of the summit. A smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. Only a few eruptions have been recorded in historical time, the first a small explosive eruption from the summit crater in 1911. An eruption producing a lava dome that eventually covered much of the floor of the inner summit crater began in December 1998.